VOR stands for VOR Test facility. VOT transmits test signal which are used to determine the operational status and accuracy of a VOR receiver. This check can be done on ground as well as in air with some restrictions.
VOT Check procedure with OBS – Omni Bearing Selector:
With course deviation indicator centered OBS should read “0 degree” and “from” indication or “180 degree” and “to” indication.
VOT Check procedure with RMI:
It indicates “180 degree” on any OBS setting.